• The Korean Journal of Physiology and Pharmacology
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• v.4 no.6
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• pp.463-469
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• 2000

It has been well known that 4-aminopyridine (4-AP) has an excitatory effect on vascular smooth muscle due to causing membrane depolarization by blocking $K^+-channel$. However, we observed that 4-AP had an inhibitory effect on the mesenteric artery of rat. Therefore, we investigated the mechanism of 4-AP-induced vasorelaxation. The mesenteric arcuate artery and its branches were isolated and cut into ring. The ring segment was immersed in HEPES-buffered solution and its isometric tension was measured. 4-AP $(0.1{\sim}10\;mM)$ induced a concentration-dependent relaxation, which was unaffected by NO synthase inhibitor, $N^G-nitro-L-arginine$ methylester $(100\;{\mu}M)$ or soluble guanylate cyclase inhibitor, methylene blue $(100\;{\mu}M).$ Glibenclamide $(100\;{\mu}M)$, ATP-sensitive $K^+$ channel blocker, did not exert any effect on the 4-AP-induced vasorelaxation. 4-AP relaxed the sustained contraction induced by 100 mM $K^+$ or $Ca^{2+}$ ionophore, A23187 $(100\;{\mu}M)$ in a dose-dependent manner. In addition, 4-AP significantly decreased the phasic contractile response to norepinephrine in the absence of extracellular $Ca^{2+}$. However, 4-AP did not block the $^{45}Ca$ influx of rat aorta. From the above results, we suggest that 4-AP may not block the $Ca^{2+}$ influx through $Ca^{2+}-channel,$ but act as a nonspecific vasorelaxant in arterial smooth muscle.

• Korean Journal of Pharmacognosy
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• v.36 no.1 s.140
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• pp.17-20
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• 2005

We previously reported that the exogenous administration of cumambrin A, a sesquiterpene lactone from the dried flowers of Chrysanthemum boreale Makino has a pharmacological effect on normalization of blood pressure in the spontaneously hypertensive rats (SHR). In the present study, we further investigated the effect of cumambrin A on the relaxation of phenylephrine-induced precontracted rat aortic artery rings. The potency of cumambrin A was than compared to verapamil, a well known $Ca^{2+}-channel$ blocker. The results demonstrate that the isolated rat aortic arteries are relaxed to basal tension at a concentration of $5{\times}10^{-5}\;M$ cumambrin A treatment. The results also show that the phenylephrine-induced contraction is inhibited by a pretreatment of cumambrin A. Co-treatment of cumambrin A and verapamil showed a strong synergetic effect on the relaxation of rat aortic artery rings. Thus, these data demonstrate that cumambrin A is a potent relaxant of rat aortic smooth muscle and suggest that cumambrin A modulates intracellular or extracellular $Ca^{2+}$ mobilization.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.3
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• pp.797-801
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• 2005

While conducting an in vitro screening of various medicinal plant extracts, an aqueous extract of Rosa rugosa Radix (ARR) was found to exhibit a distinct vasorelaxant activity. ARR induced a concentration-dependent relaxation of the phenylephrine-precontracted aorta. This effect disappeared with the removal of functional endothelium. Pretreatment of the aortic tissues with NG-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]-oxadiazole-[4,3-]-quinoxalin-1-one (ODQ) completely inhibited the relaxation induced by ARR. ARR-induced vascular relaxations were also markedly attenuated by addition of diltiazem or verapamil. However, the relaxant effect of ARR was not blocked by pretreatment with indomethacine, tetraethylammonium (TEA), glibenclamide, atropine, or propranolol. Taken together, the present study suggests that ARR dilates vascular smooth muscle via endothelium-dependent NO/cGMP signaling.

• The Korean Journal of Physiology
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• v.19 no.2
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• pp.155-160
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• 1985

Dantrolene sodium(DS) is a long acting skeletal muscle relaxant which has been successfully used to control muscle spasticity in patients with various neurological disorders. However, its use is associated with hepatotoxicity. Tissue sulfhydryl group has many important roles for cellular integration and glutathione serves as a substrate for the detoxification metabolism. The purpose of this study were to investigate the effect of DS on tissue sulfhydrl group and glutathione content. Foully albino rats were divided into two groups ; saline treated (control) and DS treated groups. DS dissolved in saline was administered orally. All rats were sacrificed after 7. 14. 21 and 28 days of DS ana saline treatment by dacapitation ana liver was removed for the enzyme preparation. Total and nonprotein sulfhydryl were measured by the method of Sedlak and Lindsay (1968). Total glutathione content was assayed according to the method described by Tietze (1969) and glutathione reductase was assayed according to the method of Racker (1955), The results obtained are summarized as follows : DS administration significantly depressed the total, protein and nonprotein sulfhydryl content in liver. There were significant reduction of both total glutathione content and glutathione reductase activity in liver. On the basis of the above results it may be speculated that the toxicity of DS are well correlated with tissue sulfhydryl content and glutathione reductase activity.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.136-140
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• 1994

To prove the hypothesis that NO- and N $O_2$-carrying molecules potentiate photorelaxation by generating NO, investigation was carried out using isolated rabbit and human corpus cavernosum. Corporal smooth muscle, in the presence or absence of endothelium, relaxed only slightly upon ultraviolet light (366 nm) irradiation. But, NO-and/or N $O_2$-containing compounds such as streptozotocin and $N^{G}$-nitro-L-arginine methyl ester significantly (p<0.01) enhanced photorelaxation in this tissue. In addition, $N^{G}$-nitro-D-arginine methyl ester, known to lack inhibitory action on NO synthase, showed concentration-dependent potentiation of the photorelaxation. Oxygen radical generating system via copper＋ascorbic acid and guanylate cyclase inhibitor, methylene blue, significantly (p<0.05) inhibited the streptozotocin-potentiated photorelaxation. Nitrite was accumulated by photolysis of streptozotocin, $N^{G}$-nitro-L-arginine methyl ester and $N^{G}$-nitro-D-arginine methyl ester, in a concentration and exposure time dependent manner. These observations indicate that NO is a potent relaxant of rabbit and human corpus cavernosum and further support the hypothesis that NO is released by photolysis from NO- and N $O_2$-carrying molecules.lecules.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.174-183
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• 1996

The general pharmacological properties of Artemisia extract powder (DA-9601) produced from Artemisia asiatica leaves were investigated in mice, rats, guinea pigs and rabbits. DA-9601 at the dose of 800 mg/kg po had no influences on general behaviour, barbital sleeping time and motor coordination of mice. The material at the oral dose of 800 mg/kg did exhibit neither analgesic action nor hypothermic effect. Anticonvulsant action, muscle relaxant action and the effect on intestinal propulsion were not identified at 800 mg/kg po. In the isolated ileum and trachea of guinea pig, the material did not show direct erect and inhibitory action of chemically or electrically stimulated contraction at the concentration of $2\times10^{-5}$g/ml. The sinus rates of atria and contractility of papillary muscle of guinea pig were not influenced by DA-9601 at a dose of $2\times10^{-5}$g/ml. No influences on blood pressure and respiration were observed at 40 mg/kg iv, in rabbits. However, transient decreases in blood pressure of rabbits were observed as given 120 mg/kg in iv route with slight respiratory depression, and slight diuretic effect could be found without any changes in $Na^+$ and $K^+$ excretion.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.3
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• pp.227-234
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• 2000

Many reports suggest that neurotensin (NT) in the gastrointestinal tract may play a possible role as a neurotransmitter, a circulating hormone, or a modulator of motor activity. NT exerts various actions in the intestine; it produces contractile and relaxant responses in intestinal smooth muscle. This study was designed to investigate the effect of NT on motility of antral circular muscle strips in guinea-pig stomach. To assess the role of $Ca^{2+}$ influx in underlying mechanism, slow waves were simultaneously recorded with spontaneous contractions using conventional intracellular microelectrode technique. At the concentration of $10^{-7}$ M, where NT showed maximum response, NT enhanced the magnitude $(863{\pm}198%,\;mean\;SEM,\;n=13)$ and the frequency $(154{\pm}10.3%,\;n=11)$ of spontaneous contractions. NT evoked a slight hyperpolarization of membrane potential, tall and steep slow waves with abortive spikes $(278{\pm}50%,\;n=4).$ These effects were not affected by atropine $(2\;{\mu}M),$ guanethidine $(2\;{\mu}M)$ and tetrodotoxin (0.2μM). NT-induced contractile responses were abolished in $Ca^{2+}-free$ solution and reduced greatly to near abolition by $10\;{\mu}M$ of verapamil or 0.2 mM of $CdCl_2.$ Verapamil attenuated the effects of NT on frequency and amplitude of the slow waves. Taken together, these results indicate that NT enhances contractility in guinea-pig gastric antral circular muscle and $Ca^{2+}$ influx through the voltage-operated $Ca^{2+}$ channel appears to play an important role in the NT-induced contractile mechanism.

• Journal of Yeungnam Medical Science
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• v.4 no.2
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• pp.155-157
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• 1987

A 25 years old male patient was experienced Trough method operation to correct of Tracheal stenosis following Tracheostomy. After admission, a No.3 Magill plastic portex tube had been placed in the previous tracheostomy opening. Stenotic narrowing portion was noted low trachea (about 3.5cm above carina) Despite of narrowing of the lesion, anesthetic course was uneventful with oxygen, halothane and non depolarized muscle relaxant by controlled respiration. Postoperative coures were also favorable With adequate respiratory cares and blood gas analyzed.

• Journal of The Korean Dental Society of Anesthesiology
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• v.12 no.3
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• pp.177-181
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• 2012

Amyotrophic lateral sclerosis (ALS) is one of the major neurodegenerative diseases that involves degeneration at all levels of the motor system- from the cortex to the anterior horn of the spinal cord. Patients with ALS often have difficulty of ambulation for dental treatment though they have poor oral hygiene state. General anesthesia may cause respiratory problem due to its high sensitivity to muscle relaxant and weakened upper airway. In this case report, 38-year-old female patient with ALS required many dental treatments. Conscious sedation with intravenous target controlled infusion method was successfully employed and patient was discharged without any complications.

• Biomolecules & Therapeutics
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• v.5 no.3
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• pp.292-298
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• 1997

General pharmacological properties of ι-muscone, the major component of musk, were investigatedin mice, rats and guinea pig. The administration of ι-muscone (1, 10, 100 mg/kg, p.o.) in mice had no effects in general behaviors, and no influences on analgesic actions and normal body temperature. Muscle relaxant action, intestinal propulsion and gastric secretion were not observed even at the high dose of 100 mg/kg. ι-Muscone (1, 10, 100 mg/kg, p.o.) given to conscious rats showed no effect on mean blood pressure and heart rate. It showed no direct effect at 2.4$\times$10.3 mg/ml and 2.4$\times$10-2 mg/ml in isolated uterus of rats and ileum of guinea pig, and also had no inhibition of contraction induced by oxytocin and histamine.